Congenital heart diseases
Bringing a new puppy into the family is an exciting time and should be a time of great
joy. It can be particularly distressing to find that your new arrival has a problem. It is
important that you get your new puppy checked over by your vet so that any obvious
problems can be identified before you become too attached to it.
What is a congenital disease?
Congenital defects are caused by abnormal development of the foetus and disease is present from the
time that the animal is born. However, although the disease is present from birth, signs may not be noticed
until later in life. Congenital defects can occur in any part of the body and the heart is no exception. The
heart is a complicated structure and as it develops there are many things that can go wrong.
Why has my pet got heart disease?
Around 1 in 200 dogs have a congenital heart problem. No-one knows why the heart develops abnormally
in some animals. It is probably usually the result of a combination of environmental conditions and genetic
factors. Some diseases are more common in particular breeds and so it is likely that they are partly passed
from parents to offspring. For this reason animals with congenital diseases should not be allowed to breed.
What are the signs of heart disease?
If defects are severe then signs can be marked, but in some cases you may not ever know that there is
anything wrong with your pet. Often one of the first signs of a heart defect is a heart murmur detected by a
vet during routine examination. When you buy a new puppy you should take them to your vet so that your
vet can check them over. Your vet should listen to their heart and will be able to tell if a murmur is present.
However there are some diseases that cause no signs in the early stages. If heart disease progresses
then an animal with a congenital condition can go on to develop heart failure. This may occur relatively
quickly within the first few weeks of months of life if the defect is serious. However in many cases no signs
are shown until the animal reaches adulthood.
Which heart diseases are common?
There are a number of congenital heart diseases and some of these more commonly affect some breeds
of dogs than others. The diseases are caused by abnormal development of the blood vessels (abnormal
connections or narrowing), the valves or as a result of abnormal connection between different parts of the
heart (hole in the heart). The most common forms of congenital heart defect include PDA (patent ductus
arteriosus) where there is a communication between blood supply into and out of the heart; narrowing of
the large blood vessels taking blood away from the heart - to the lungs (pulmonic stenosis) or to the body
(aortic stenosis). Sometimes there is abnormal development of the valves between the various chambers
of the heart usually affecting the mitral valve (mitral dysplasia). It is rare for dogs to have a 'hole in the
heart'.
How do vets diagnose heart defects?
If your vet detects a heart murmur on examination they will need to do further tests in order to find out what
is causing the problem. X-rays might help but ultrasound will be needed to find out exactly what is wrong
with the heart. Your vet may need to refer your pet to a vet who specialises in heart disease for detailed
examination. This will allow the best treatment plan to be formulated.
Can congenital heart disease be treated?
Unfortunately the long-term outlook for animals with severe congenital heart disease is usually not good.
The only cure for heart defects is surgical correction. Some defects can be corrected by an operation, for
example to tie off an abnormal blood vessel - for other defects there is no specific treatment. In cases of
pulmonic stenosis it may be possible to reduce the narrowed valve by stretching it using a special catheter
(balloon valvuloplasty). In some cases animals have no problems with their disease and can live with the
condition. If animals develop heart failure then this can be managed with drugs to control signs.
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Congenital heart diseases
Will my pet get better?
If your pet can have surgery to correct their heart defect they will probably need to be sent to a specialist
surgeon. However recovery from the operation is usually rapid and they may be back to normal in a week
or two. Unfortunately if there is no surgical option for your pet then they may need drug treatment for the
rest of their life. It can be very distressing to watch a young animal suffer with heart disease and, if there is
no treatment for your pet, you should discuss with your vet whether euthanasia might be the kindest
option.
If you want any other information on health issues concerning your pet Vetstream advise
you to contact your local veterinary practice.
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